Men's Osteoporosis Support Group

To participate in an online research project Click here.

Bone turnover markers--two studies

J Clin Endocrinol Metab. 2009 Jan 13. [Epub ahead of print], Prediction of Changes in Bone Mineral Density in Postmenopausal Women Treated With Once-Weekly Bisphosphonates. Burnett-Bowie SA and others. PMID: 19141590. This is a study to determine if testing bone turnover markers (BTMs) could be a proxy for dual-energy X-ray absorptiometry (DXA) testing for individuals taking once-weekly bisphosphonates for osteoporosis. The idea being that BTMs would provide quicker results as to whether medication was effective, since DXA results are not normally definitive for one or two years.

This was a 24-month study comparing the tertile percent change from baseline in BTMs at 3 or 6 months, and association of several baseline clinical characteristics, with 24-month percent change from baseline in BMD, and with percentage of patients showing BMD non-response (defined as BMD loss at 2 or more of 4 sites) at 24 months. [Note that in osteoporosis bone turnover is excessive, so the bisphosphonate's effect is to reduce the turnover, which would be reflected in lower BTM numbers if the medication is effective]. The authors found, "Patients in the tertile with the greatest decrease in each of the BTMs had the greatest mean increase in BMD and the lowest percentage of BMD non-responders at 24 months." Additionally, smaller 3-month reductions from baseline in CTX, bone ALP, and PINP were associated with non-response to therapy. And they concluded, "In groups of patients, short term changes in markers of bone turnover appear to be predictors of longer term BMD response and non-response to bisphosphonate therapy."

Editor's comments. BTMs are one category of biochemical markers that can be tested to determine if bone is either forming or resorbing (turning over). There is an explanation of many of these markers at this Update. Also if you put "biochemical" into the FreeFind search engine you'll find several other articles that discuss biochemical markers. BTMs are not 100% specific, but, from the results of this study, they can be helpful to determine if treatment is effective without waiting a full year or two to get a DXA done. Of importance is to have a baseline test done before first taking one of the approved osteoporosis medications. Then at the three-month time an additional test could provide helpful information regarding your response to therapy. In my experience it is not the normal protocol to have the BTM testing done, either at baseline or three months, so the patient will have to ask for this. If there is a significant reduction in turnover, you could probably feel pretty comfortable that you are responding adequately. If not, then you may want to investigate this with additional BTMs in three more months, or with a one-year DXA, as you and your care provider decide the best approach. If you aren't responding to one medication, there are several others you can try. Or you can switch from the oral form to I.V. medication, a non-bisphosphonate, such as Forteo, etc. Here is a nice breakdown of all the FDA-approved medications at NOF.

Int J Clin Pract. 2009 Jan;63(1):19-26, Evidence-based guidelines for the use of biochemical markers of bone turnover in the selection and monitoring of bisphosphonate treatment in osteoporosis: a consensus document of the Belgian Bone Club. Bergmann P and others. PMID: 19125989. This paper discusses consensus guidelines regarding the use of BTMs or bone mineral density (BMD) as methods to start osteoporosis therapy, or to monitor its success. The authors conclude, "Consensus regarding the use of BTM resulted in guidelines for clinical practice. BMD determines the indication to treat osteoporosis. BTM reflect treatment efficiency and can be used to motivate patients to persist with their medication."

Editor's comments. In short, the paper's conclusions agree pretty much with those of the Burnett-Bowie and others article: That BTMs have some use to monitor the response to osteoporosis therapy, and, not mentioned above, they can be used to motivate the patient to continue with therapy. But they state that DXA should be the primary determining tool to decide to start therapy since it provides BMD. Note they also mention that Serum C-terminal cross-linked telopeptide of type I collagen (CTX), procollagen 1 N terminal extension peptide, and bone specific alkaline phosphatase (BSALP) appear to be the most effective BTMs, in agreement with the first article, above.

Note that both these articles direct their discussion entirely about women, but there is nothing gender-specific about either DXA or BTMs, so the results apply equally to men.

Return to Home